Apparatus and system

ABSTRACT

An apparatus is disclosed that includes a receiver that receives downlink control information that is used for scheduling of a downlink shared channel, via a downlink control channel in a control resource set. The apparatus also includes a processor that determines a starting location in a time domain of the downlink shared channel based on the downlink control information. The apparatus further includes an output device that performs output based on downlink data signal in the downlink shared channel. When the downlink shared channel overlaps with the control resource set, a resource to which the downlink control information is mapped is not available for the downlink shared channel and wherein a field value in the downlink control information indicates an index for designating one of a plurality of starting locations that are provided in advance. In another aspect, a system is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 16/482,902, filed on Aug. 1, 2019, which is anational phase application of PCT/JP2018/003539, filed on Feb. 2, 2018,which claims priority to Japanese Patent Application No. 2017-017971,filed on Feb. 2, 2017. The contents of these applications are herebyincorporated by reference in their entirety.

TECHNICAL FIELD

The present invention relates to an apparatus and a system innext-generation mobile communication systems.

BACKGROUND ART

In the UMTS (Universal Mobile Telecommunications System) network, thespecifications of long-term evolution (LTE) have been drafted for thepurpose of further increasing high speed data rates, providing lowerlatency and so on (see non-patent literature 1). In addition, successorsystems of LTE are also under study for the purpose of achieving furtherbroadbandization and increased speed beyond LTE (referred to as, forexample, “LTE-A (LTE-Advanced),” “FRA (Future Radio Access),” “4G,”“5G,” “5G+(plus),” “NR (New RAT),” “LTE Rel. 14,” “LTE Rel. 15 (or laterversions),” and so on).

In existing LTE systems (for example, LTE Rel. 8 to 13), downlink (DL)and/or uplink (UL) communication are performed using 1-ms subframes(also referred to as “transmission time intervals (TTIs)” and so on).These subframes are the time unit for transmitting one channel-encodeddata packet, and serve as the unit of processing in, for example,scheduling, link adaptation, retransmission control (HARQ: HybridAutomatic Repeat reQuest) and so on.

A radio base station controls the allocation (scheduling) of data for auser terminal, and reports the schedule of data to the user terminalusing downlink control information (DCI). The user terminal controls thereceipt of DL data and/or transmission of uplink data based on thedownlink control information. To be more specific, based on the downlinkcontrol information, the user terminal receives downlink data in thesame subframe as the downlink control information, or transmits uplinkdata in a predetermined subframe in a predetermined period (for example,4 ms later).

CITATION LIST Non-Patent Literature

-   Non-Patent Literature 1: 3GPP TS36.300 V8.12.0 “Evolved Universal    Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial    Radio Access Network (E-UTRAN); Overall description; Stage 2    (Release 8),” April, 2010

SUMMARY OF INVENTION Technical Problem

Future radio communication systems (for example, LTE Rel. 14, 15 orlater versions, 5G, NR, etc.) are assumed to control data schedulingbased on different configurations from those of existing LTE systems(for example, LTE Rel. 13 or earlier versions).

For example, in existing LTE systems, DL data is scheduled in eachsubframe based on downlink control information that is transmitted everypredetermined transmission time interval (subframe).

The downlink control information is allocated in a downlink controlchannel (PDCCH: Physical Downlink Control Channel) that is defined overa predetermined number of symbols (one to three symbols) from the headof a subframe, over the system band.

Meanwhile, in future radio systems, a study is in progress to change theallocation of the above downlink control information and/or the downlinkcontrol channel and to use the radio resources that have becomeavailable then. In such radio communication systems, how to control thelocation to allocate data in each slot is the problem.

The present invention has been made in view of the above, and it istherefore an object of the present invention to provide a user terminaland a radio communication method, whereby data communication processescan be performed adequately even when different downlink controlchannels from those of existing LTE systems are configured.

Solution to Problem

A user terminal, according to one aspect, has a receiving section thatreceives downlink control information, which is transmitted via adownlink control channel in a control resource set configured in apredetermined resource block, and a control section that controlsreceipt of downlink data scheduled in a predetermined frequency field,based on the downlink control information, and the downlink data isallocated over the predetermined frequency field from the same timelocation, or allocated to the predetermined frequency field from varyingtime locations.

Advantageous Effects of Invention

According to the present invention, even when different downlink controlchannels from those of existing LTE systems are configured, datacommunication processes can be performed adequately.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A and 1B are diagrams to explain the frequency band formonitoring downlink control channels;

FIG. 2 is a diagram to illustrate allocation of downlink controlchannels (control resource sets) and DL data, which is different than inexisting LTE systems;

FIG. 3 is a diagram to illustrate locations where control resource setsand DL data are allocated, according to a first aspect of a firstembodiment of the present invention;

FIG. 4 is a diagram to illustrate locations where control resource setsand DL data are allocated, according to an alternative example of thefirst aspect of the first embodiment;

FIG. 5 is a diagram to illustrate locations where control resource setsand DL data are allocated, according to a second aspect and a thirdaspect of the first embodiment;

FIG. 6 is a diagram to illustrate locations where control resource setsand DL data are allocated, according to the second aspect and the thirdaspect of the first embodiment;

FIG. 7 is a diagram to illustrate locations where control resource setsand DL data are allocated, according to a second embodiment of thepresent invention;

FIGS. 8A and 8B are diagrams to illustrate locations where controlresource sets, common control channels and DL data are allocated,according to a second reporting method of a third embodiment of thepresent invention;

FIGS. 9A and 9B are diagrams to illustrate locations where controlresource sets, common control channels and DL data are allocated,according to an alternative example of the second reporting method ofthe third embodiment;

FIG. 10 is a diagram to illustrate an example of a schematic structureof a radio communication system according to an embodiment of thepresent invention;

FIG. 11 is a diagram to illustrate an example of an overall structure ofa radio base station according to an embodiment of the presentinvention;

FIG. 12 is a diagram to illustrate an example of a functional structureof a radio base station according to an embodiment of the presentinvention;

FIG. 13 is a diagram to illustrate an example of an overall structure ofa user terminal according to an embodiment of the present invention;

FIG. 14 is a diagram to illustrate an example of a functional structureof a user terminal according to an embodiment of the present invention;and

FIG. 15 is a diagram to illustrate an example hardware structure of aradio base station and a user terminal according to one embodiment ofthe present invention.

DESCRIPTION OF EMBODIMENTS

In existing LTE systems, a base station transmits downlink controlinformation (DCI) to a UE using a downlink control channel (for example,PDCCH (Physical Downlink Control Channel), enhanced PDCCH (EPDCCH(Enhanced PDCCH), etc.). Transmission of downlink control informationmay be interpreted as transmission of a downlink control channel.

DCI may be scheduling information, including at least one of, forexample, data-scheduling time/frequency resources, transport blockinformation, data modulation scheme information, HARQ retransmissioninformation, demodulation RS information, and so on. DCI that schedulesreceipt of DL data and/or measurements of DL reference signals may bereferred to as “DL assignment” or “DL grant,” and DCI that schedulestransmission of UL data and/or transmission of UL sounding (measurement)signals may be referred to as “UL grant.” DL assignments and/or ULgrants may include information related to the resources, sequences andtransmission formats of channels for transmitting UL control signals(UCI: Uplink Control Information) such as HARQ-ACK feedback in responseto DL data, channel measurement information (CSI: Channel StateInformation) and so on. Also, apart from DL assignments and UL grants,DCI for scheduling UL control signals (UCI: Uplink Control Information)may be defined.

A UE is configured to monitor a set of a predetermined number ofdownlink control channel candidates. To “monitor” in this case means,for example, attempting to decode each downlink control channel for atarget DCI format, in the set. Such decoding is also referred to as“blind decoding (BD)” or “blind detection.” Downlink control channelcandidates are also referred to as “downlink control channel allocationcandidates,” “BD candidates,” “(E)PDCCH candidates,” “DCI candidates,”and so on.

The set of downlink control channel candidates (multiple downlinkcontrol channel candidates) to be monitored is also referred to as a“search space.” A base station places DCI in a predetermined downlinkcontrol channel candidates included in the search space. The UE performsblind decoding for one or more candidate resources in the search space,and detects the DCI addressed to the UE. The search space may beconfigured by high layer signaling that is common between users, or maybe configured by user-specific high layer signaling.

In existing LTE systems, a plurality of aggregation levels (ALs) areprovided in a search space for the purpose of link adaptation. The ALscorrespond to the numbers of control channel elements (CCEs)/enhancedcontrol channel elements (ECCEs: Enhanced CCEs) that constitute DCI.Also, the search space is configured so that there are multiple downlinkcontrol channel candidates for a given AL. Each downlink control channelcandidate is comprised of one or more resource units (CCEs and/orECCEs).

Cyclic redundancy check (CRC) bits are attached to the DCI. The CRC ismasked (scrambled) using UE-specific identifiers (for example,cell-radio network temporary identifiers (C-RNTIs)) or a system-commonidentifier. The UE can detect the DCI where the CRC is scrambled usingthe C-RNTI for the subject terminal, and the DCI where the CRC isscrambled using the system-common identifier.

Also, as for the search spaces, there are a common search space (C-SS)that is configured for UEs on a shared basis, and a UE-specific searchspace (UE-SS) that is configured for each UE.

Future radio communication systems (for example, LTE Rel. 14, 15 and/orlater versions, 5G, NR, etc.) are under study to introduce multiplenumerologies, not a single numerology.

A numerology may refer to a set of communication parameters thatcharacterize the design of signals in a given RAT (Radio AccessTechnology), the design of the RAT and so on, and may be parameters thatrelate to the frequency direction and/or the time direction, such assubcarrier spacing (SCS), symbol duration, cyclic prefix duration,subframe duration and so on. For example, future radio communicationsystems may support multiple SCS spacings such as 15 kHz, 30 kHz, 60kHz, 120 kHz and 240 kHz.

Also, future radio communication systems are being studied to introducetime units (also referred to as “subframes,” “slots,” “mini-slots,”“subslots,” “transmission time intervals (TTIs),” “short TTIs,” “radioframes” and so on) that are the same and/or different from those ofexisting LTE systems (LTE Rel. 13 or earlier versions), while supportingmultiple numerologies and so on.

Note that a TTI may represent the time unit for use whentransmitting/receiving transport blocks for transmitting/receiving data,code blocks and/or codewords. Assuming that a TTI is provided, theperiod of time (for example, the number of symbols) where the transportblocks, the code blocks and/or the codewords of data are actually mappedmay be shorter than the TTI.

For example, when a TTI is formed with a predetermined number of symbols(for example, fourteen symbols), the transport blocks, the code blocksand/or the codewords of transmitting/receiving data can be transmittedand received in one or a predetermined number of symbol periods amongthese. If the number of symbols in which transport blocks, code blocksand/or codewords of transmitting/receiving data are transmitted/receivedis smaller than the number of symbols constituting the TTI, referencesignals, control signals and so on can be mapped to symbols in the TTIwhere no data is mapped.

Subframes may serve as a time unit having a predetermined time duration(for example, 1 ms), irrespective of which numerology is used by (and/orconfigured in) the user terminal (for example, UE (User Equipment)).

On the other hand, slots may serve as a time unit that is based on thenumerology used by the UE. For example, if the subcarrier spacing is 15kHz or 30 kHz, the number of symbols per slot may be seven or fourteen.When the subcarrier spacing is 60 kHz or greater, the number of symbolsper slot may be fourteen. In addition, a slot may include a plurality ofmini-slots (subslots).

Generally, subcarrier spacing and symbol duration hold a reciprocalrelationship. Therefore, as long as the number of symbols per slot (ormini-slot (subslot)) stays the same, the higher (wider) the subcarrierspacing, the shorter the slot length, and the lower (narrower) thesubcarrier spacing, the longer the slot length. Note that “subcarrierspacing is high” may be paraphrased as “subcarrier spacing is wide,” and“subcarrier spacing is low” may be paraphrased as “subcarrier spacing isnarrow.”

Furthermore, in future radio communication systems, communication maynot be performed using the whole system band in a predetermined carrierat all times, and it is more likely that communication will becontrolled by configuring predetermined frequency fields (also referredto as “frequency bands”), dynamically or semi-statically, depending onthe purpose of communication and/or the communicating environment.

Now, in conventional LTE systems, a downlink control channel (ordownlink control information) is transmitted using the whole systembandwidth (see FIG. 1A). Therefore, regardless of whether or not DL datais allocated in each subframe, a UE needs to monitor the whole systembandwidth to receive (blind-decode) downlink control information.

By contrast with this, in future radio communication systems, downlinkcontrol information for a given UE needs not be necessarily allocated tothe whole system band and transmitted, and, instead, transmission ofdownlink control information may be controlled by configuring apredetermined frequency field in the UE (see FIG. 1B). The predeterminedfrequency filed that is configured in the UE may be referred to as a“control resource set (CORSET),” a “control subband,” a “search spaceset,” a “search space resource set,” a “control field,” a “controlsubband,” an “NR-PDCCH field,” and so on.

A control resource set is constituted by predetermined resource units,and can be configured to be equal or less than the system bandwidth(carrier bandwidth). For example, a control resource set may beconstituted by one or more RBs (PRBs and/or VRBs) in the frequencydirection. Here, an RB refers to, for example, a frequency resourceblock unit comprised of twelve subcarriers. The UE can monitor fordownlink control information within the range of the control resourceset, and control receipt. By this means, in the receiving process ofdownlink control information, the UE does not have to keep monitoringthe whole system bandwidth at all times, so that its power consumptioncan be reduced.

Also, a plurality of control resource sets may be arranged in one slot.For example, in the example illustrated in FIG. 2, control resource sets1 and 2 are arranged in one slot. Each control resource set is comprisedof two symbols. These multiple control resource sets may be configuredin completely or partially overlapping frequency resources, or may beconfigured in different frequency resources. Also, these multiplecontrol resource sets may be formed with different numbers of OFDMsymbols. Also, two or more control resource sets, as well as searchspaces included therein, may be configured in a given UE. Although, forease of explanation, cases will be described below in which everycontrol resource set contains a different UE's (or UE group's) searchspace, this is in practice not the case. In the example illustrated inFIG. 2, control resource set 1 contains downlink control information forUEs #1 to #3. Control resource set 2 contains downlink controlinformation for UEs #4 and #5.

The DL data illustrated in FIG. 2 is DL data for one of UEs #1 to #5.Furthermore, in control resource sets 1 and 2, resources other than theresources for downlink control signals for UEs #1 to #5 are not used totransmit downlink control information.

Assuming that downlink control information is transmitted using controlresource sets, the present inventors have focused on where the locationsto allocate scheduled data (for example, the location where theallocation starts) should be configured, and come up with the idea ofallocating data in the same time location or different time locations ina predetermined frequency field (multiple resource blocks).

Now, embodiments of the present invention will be described below indetail with reference to the accompanying drawings. Although cases willbe illustrated with the following embodiments where data scheduling iscontrolled on a per slot basis, other time units are equally applicable(for example, subframes, mini-slots, subslots, transmission timeintervals (TTIs), short TTIs, radio frames, etc.).

First Embodiment

According to a first embodiment of the present invention, when downlinkcontrol information is transmitted using control resource sets, thelocation where scheduled data starts being allocated is configured inthe same time location in a predetermined frequency field (multipleresource blocks). FIG. 3 and FIG. 4 are diagrams to explain a firstaspect of the first embodiment. FIG. 5 and FIG. 6 are diagrams toexplain a second aspect and a third aspect of the first embodiment.

(First Aspect) FIG. 3 illustrates DL data, the schedule of whichscheduling is reported in downlink control information of UE #1. DL datais configured such that the starting location in the scheduled resourceblock (in predetermined frequency field f1) is the same time location.

When scheduling DL data, a base station (gNB) determines theabove-mentioned starting location so that the DL data does not overlap(overlay) any of downlink control information (DCI), a search space (SS)and a control resource set. By this means, on the user terminal (UE)side, there is no need to perform the demodulation process caused by theabove overlap, and therefore power consumption can be reduced. Note thatthe amount of radio resources used increases in order of DCI, an SS, anda control resource set.

Furthermore, in FIG. 3, the location where scheduled DL data starts isconfigured in the location where control resource set 1 ends, but thisstarting location may be configured in control resource set 1. Forexample, if the downlink control information for UE #3 in FIG. 3 is notallocated and the corresponding resource is unoccupied, as illustratedin FIG. 4, the starting location may be configured in the second symbolof a control resource set. In this case, the DL data does not overlapwith the downlink control information of UE #1, so that the gNB does nothave to perform overlap-induced processes. In addition, the DL data canbe transmitted using unoccupied resources in the control resource set.

According to the first aspect, it is possible to allocate (schedule) DLdata by reducing the fields to allocate control information, so that itis possible to reduce the overhead and improve the efficiency of the useof resources. Accordingly, even when different downlink control channelsfrom those of existing LTE systems are configured, data communicationprocesses can be performed adequately.

(Second Aspect)

While, according to the above-described first aspect, DL data isconfigured so as not to overlap (overlay) with any of downlink controlinformation (DCI), a search space (SS) and a control resource set, witha second aspect of the first embodiment, DL data can (may) overlap oneof downlink control information (DCI), a search space (SS) and a controlresource set.

FIG. 5 illustrates DL data, the schedule of which is reported indownlink control information for UE #3. The starting location of the DLdata is configured in the second symbol of a control resource set. As isapparent from this drawing, the downlink control information for UE #3overlaps a part of the DL data.

That is, upon scheduling DL data for UE #3, the gNB has to determine thestarting location of the DL data, part of the DL data is permitted tooverlap the downlink control information for UE #3. In this case, thegNB applies rate matching to the overlapping part. That is, ratematching is applied to the transmitting DL data based on the premisethat no DL data can be arranged on resources where DCI is mapped.

The UE can detect downlink control information addressed to the UE byperforming blind decoding in the search space. Accordingly, the UEdetects DCI addressed to the UE, and identifies the resource for the DLdata scheduled by this DCI. If the resources of the DCI and thescheduled DL data overlap, de-rate matching (rate matching process) isapplied to DL data that is received, based on the premise that no DLdata is arranged on the resource where the DCI is mapped.

Meanwhile, as illustrated in FIG. 6, downlink control information thatis not directed to the UE may overlap the DL data. FIG. 6 illustrates DLdata, the schedule of which scheduling is reported in downlink controlinformation for UE #1. The starting location of the DL data isconfigured at the beginning of the slot—that is, the starting locationof a control resource set.

In this case, as illustrated in this drawing, downlink controlinformation for UE #2 and UE #3 overlap the DL data for UE #1.Generally, a UE cannot detect DCI for other UEs. This is because the CRCcheck code varies per UE. Consequently, in the DL data scheduled for UE#1, the gNB punctures the part of the DL data where downlink controlinformation for

UE #2 and UE #3 is mapped. In this case, UE #1 performs thereceiving/decoding processes without recognizing that part of the DLdata has been punctured. If the coding rate is small enough, or if theamount of punctured resources is substantially small compared to theamount of scheduled resources, the deterioration due to this puncturingcan be reduced. Alternatively, the gNB may puncture the downlink controlinformation for UE #2 and UE #3 so as to prioritize the DL datascheduled for UE #1. In this case, since the DL data to send to UE #1 isnot punctured, the deterioration of performance can be reduced.

Note that, although this will be described later with a third embodimentof the present invention, the punctured part in DL data may be reportedfrom the gNB to the UE through L1 signaling. In this case, DCI may beused. The UE depunctures (puncturing process) the punctured part of theDL data. Also, although a case has been described with the second aspectwhere downlink control information and DL data overlap, this downlinkcontrol information may be at least one of DCI, an SS, and a controlresource set. That is, the above-described rate matching and/orpuncturing process may be performed in any of DCI units, SS units, andcontrol resource set units.

According to the second aspect of the present invention described above,the starting location of DL data can be configured to overlap a controlresource set, so that the resources that have become available as aresult of reducing the fields to allocate control information can beused for data transmission, and, in addition, a greater amount of datacan be transmitted. Consequently, the efficiency of the use of resourcescan be improved. Accordingly, even when different downlink controlchannels from those of existing LTE systems are configured, datacommunication processes can be performed adequately. Also, by usingde-rate matching (rate matching process), it is possible to demodulatedownlink control information addressed to the subject terminal with highaccuracy.

(Third Aspect)

Next, a third aspect will be described. According to the third aspect,puncturing is used instead of rate matching of the second aspectdescribed above. The arrangement/structure of one slot is the same as inFIG. 5 and FIG. 6, which relate to the second aspect. Therefore, onlyparts that are different from the second aspect will be explained below.

To be more specific, in FIG. 5, downlink control information for thesubject terminal (downlink control information for UE #3) and the DLdata overlap, so that the gNB punctures the DL data in this overlappingpart. The UE detects the downlink control information addressed to theUE by performing blind decoding, and, if the DL data scheduled by thisDCI overlaps the above DCI, the UE depunctures (puncturing process) theDL data of the overlapping part.

According to the third aspect of the present invention described above,the starting location of DL data can be configured to overlap a controlresource set, so that the resources that have become available as aresult of reducing the fields to allocate control information can beused for data transmission, and, in addition, a greater amount of datacan be transmitted. Consequently, the efficiency of the use of resourcescan be improved. Accordingly, even when different downlink controlchannels from those of existing LTE systems are configured, datacommunication processes can be performed adequately.

Note that, while the second aspect that performs rate matching ispreferable from the perspective of the accuracy of demodulation, fromanother perspective, the rate matching and de-rate matching processes inthe gNB and the UE are complicated. Puncturing is a simple process thatsimply removes previously-generated data (that is, punctures specificbits, resource elements (RE), resource blocks (RB) or symbols).Therefore, according to the third aspect, the processing burden on thegNB and the UE can be lightened.

Furthermore, although a case has been described above with the thirdaspect where downlink control information overlaps DL data, thisdownlink control information may be at least one of DCI, an SS, and acontrol resource set.

Second Embodiment

According to a second embodiment of the present invention, when downlinkcontrol information is transmitted using control resource sets, thelocation where scheduled data starts being allocated is configured indifferent time locations in a predetermined frequency field (multipleresource blocks). Different time locations may be configured dependingon resource blocks, resource block groups and so on.

FIG. 7 illustrates DL data configured so that there are varying dataallocation starting locations. The schedule of the DL data is reportedin downlink control information for one of UEs #1 to #5. Thus, since thelocation to start data allocation is configured in different timelocations in a predetermined frequency field (multiple resource blocks),resources that have been made available as a result of reducing thefields to allocate control information can be used for datatransmission. Consequently, the efficiency of the use of resources canbe improved. Therefore, even when downlink control channels that aredifferent from those of existing LTE systems are configured, datacommunication processes can be performed adequately.

Note that, although the starting locations in FIG. 7 are configured sothat the DL data and the downlink control information do not overlap,this is by no means limiting. DL data and downlink control informationare permitted to overlap each other, and rate matching and/or puncturingmay be applied to the overlapped part, as in the second aspect or thethird aspect of the above-described first embodiment.

Note that, when configuring starting locations in different timelocations, it may be possible to, for example, configure one timelocation first, and change this time location (configure differentvalues) depending on resource blocks and/or resource block groups. Whenmaking changes, the difference from the configured time location isreported, so that time location can be configured depending on resourceblocks and/or resource block groups. Alternatively, a table in which aplurality of time locations are provided may be reported in advance tothe UE, and the time location may be changed based on indices reportedfrom the gNB to the UE.

Third Embodiment

The starting location in the first embodiment and the second embodimentdescribed above needs to be reported to the UE. With a third embodimentof the present invention, how to report the starting location to the UEwill be described.

(First Reporting Method)

In the first reporting method, the starting location is reported usingDCI. The starting location is indicated in a field provided in DCI. Theinformation in the field may be information that indicates the location(gap) from the beginning of the slot. Alternatively, assuming that atable in which a plurality of time locations are set forth is reportedto the UE in advance, and the information in the field may be an indexthat specifies a time location provided in this table as an entry.

According to the first reporting method, starting locations that areconfigured as appropriate depending on control resource sets and/ordownlink control information allocated to these control resource setscan be reported per slot and per UE. As a result of this, even whendifferent downlink control channels from those of existing LTE systemsare configured, data communication processes can be performedadequately.

(Second Reporting Method)

According to a second reporting method, starting locations are reportedusing a common control channel. As illustrated in FIGS. 8A and 8B, thecommon control channel may be, for example, a control signal or achannel that is different from scheduling information (DCI). The commoncontrol channel is a channel that is common to a plurality of UEs (in aUE group), and is also referred to as “common PDCCH,” “NR-common PDCCH,”and so on. Reporting using such a channel is also referred to as “commonL1 signaling” or “common signaling.”

The amount of DL data (the amount of resources scheduled) can be changedat the starting locations specified by the common control channel (FIGS.8A and 8B). Here, the DL data may be replaced with transport blocks/codeblocks (TBs/CBs) that are scheduled.

According to the second reporting method, starting locations that areconfigured as appropriate according to downlink control information(DCI) can be reported per slot. Furthermore, since it is possible toreport a starting location that is common to multiple UEs, the gNB cancontrol DL data allocation for multiple UEs (UEs in a UE group)collectively. As described above, even when downlink control channelsdifferent from those of existing LTE systems are configured, datacommunication processes can be performed adequately.

(Alternative Example of Second Reporting Method)

According to an alternative example of the second reporting method, astarting location of DL data is fixed semi-statically, and startinglocations of other DL data than this DL data are reported using theabove-described common control channel. For example, in FIGS. 9A and 9B,the starting location of DL data is fixed (fixed DL data). Meanwhile, asillustrated in FIG. 9A, the starting location of new (additional) DLdata that is allocated to a resource not overlapping the above fixed DLdata or the downlink control information may be designated using thecommon control channel.

The starting location of new DL data may be designated by the commoncontrol channel when the gNB detects that there is an unoccupiedresource between the fixed DL data and the downlink control information.

Furthermore, the starting location of new (additional) data that isdesignated using the above common control channel is by no means limitedto the downlink. For example, this designation of new data's startinglocation may be applied to uplink transmission from the UE to the gNB.

According to the alternative example of the second reporting method, inaddition to DL data/UL data where the starting location is fixedsemi-statically, new (additional) DL data/UL data that is specified by acommon control channel can be reported to multiple UEs. Consequently,the gNB can control allocation of DL data for multiple UEs (UEs in a UEgroup) collectively, so that data communication processes can beperformed adequately even when downlink control channels that aredifferent from those of existing LTE systems are configured.

According to the first reporting method described above, when the commoncontrol channel fails to be received, there is no way knowing in whichlocation DL data starts, and the DL data cannot be received. Also,according to the second reporting method, if the common control channelfails to be received, it is not possible to know the starting locationof DL data, and therefore the DL data cannot be received. By contrastnow, with an alternative example (FIG. 9A) of the second reportingmethod, even if receipt of the common control channel fails, as long asDCI is received successfully, at least a part of the DL data containedin that slot can be demodulated. This can prevent the situation wherethe UE is unable to operate at all.

The above common control channel may be the existing PCFICH. However,the PCFICH specifies the number of control channel symbols. Therefore,if the PCFICH fails to be received (decoded), neither control channelsnor data channels can be received. On the other hand, according to theabove-described alternative example of the second reporting method, evenif one of a control resource set and the common control channel fails tobe received, as long as the other one is received, it is still possibleto prevent the situations where the UE is unable to operate at all.

(Radio Communication System)

Now, the structure of the radio communication system according to oneembodiment of the present invention will be described below. In thisradio communication system, communication is performed using one or acombination of the radio communication methods according to theherein-contained embodiments of the present invention.

FIG. 10 is a diagram to illustrate an example of a schematic structureof a radio communication system according to an embodiment of thepresent invention. A radio communication system 1 can adopt carrieraggregation (CA) and/or dual connectivity (DC) to group a plurality offundamental frequency blocks (component carriers) into one, where theLTE system bandwidth (for example, 20 MHz) constitutes one unit.

Note that the radio communication system 1 may be referred to as “LTE(Long Term Evolution),” “LTE-A (LTE-Advanced),” “LTE-B (LTE-Beyond),”“SUPER 3G”, “IMT-Advanced,” “4G (4th generation mobile communicationsystem),” “5G (5th generation mobile communication system),” “FRA(Future Radio Access),” “New-RAT (Radio Access Technology),” “NR (NewRadio)” and so on, or may be seen as a system to implement these.

The radio communication system 1 includes a radio base station 11 thatforms a macro cell C1 having a relatively wide coverage, and radio basestations 12 (12 a to 12 c) that are placed within the macro cell C1 andthat form small cells C2, which are narrower than the macro cell C1.Also, user terminals 20 are placed in the macro cell C1 and in eachsmall cell C2. The arrangement of cells and user terminals 20 are notlimited to those illustrated in the drawings.

The user terminals 20 can connect with both the radio base station 11and the radio base stations 12. The user terminals 20 may use the macrocell C1 and the small cells C2 at the same time by means of CA or DC.Furthermore, the user terminals 20 may apply CA or DC using a pluralityof cells (CCs) (for example, five or fewer CCs or 6 or more CCs).

Between the user terminals 20 and the radio base station 11,communication can be carried out using a carrier of a relatively lowfrequency band (for example, 2 GHz) and a narrow bandwidth (referred toas, for example, an “existing carrier,” a “legacy carrier” and so on).Meanwhile, between the user terminals 20 and the radio base stations 12,a carrier of a relatively high frequency band (for example, 3.5 GHz, 5GHz and so on) and a wide bandwidth may be used, or the same carrier asthat used in the radio base station 11 may be used. Note that thestructure of the frequency band for use in each radio base station is byno means limited to these.

A structure may be employed here in which wire connection (for example,means in compliance with the CPRI (Common Public Radio Interface) suchas optical fiber, the X2 interface and so on) or wireless connection isestablished between the radio base station 11 and the radio base station12 (or between two radio base stations 12).

The radio base station 11 and the radio base stations 12 are eachconnected with higher station apparatus 30, and are connected with acore network 40 via the higher station apparatus 30. Note that thehigher station apparatus 30 may be, for example, access gatewayapparatus, a radio network controller (RNC), a mobility managemententity (MME) and so on, but is by no means limited to these. Also, eachradio base station 12 may be connected with the higher station apparatus30 via the radio base station 11.

Note that the radio base station 11 is a radio base station having arelatively wide coverage, and may be referred to as a “macro basestation,” a “central node,” an “eNB (eNodeB),” a “gNB,” a“transmitting/receiving point” and so on. Also, the radio base stations12 are radio base stations having local coverages, and may be referredto as “small base stations,” “micro base stations,” “pico basestations,” “femto base stations,” “HeNBs (Home eNodeBs),” “RRHs (RemoteRadio Heads),” “transmitting/receiving points” and so on. Hereinafterthe radio base stations 11 and 12 will be collectively referred to as“radio base stations 10,” unless specified otherwise.

The user terminals 20 are terminals to support various communicationschemes such as LTE, LTE-A and so on, and may be either mobilecommunication terminals (mobile stations) or stationary communicationterminals (fixed stations).

In the radio communication system 1, as radio access schemes, orthogonalfrequency division multiple access (OFDMA) is applied to the downlink,and single-carrier frequency division multiple access (SC-FDMA) isapplied to the uplink.

OFDMA is a multi-carrier communication scheme to perform communicationby dividing a frequency bandwidth into a plurality of narrow frequencybandwidths (subcarriers) and mapping data to each subcarrier. SC-FDMA isa single-carrier communication scheme to mitigate interference betweenterminals by dividing the system bandwidth into bands formed with one orcontinuous resource blocks per terminal, and allowing a plurality ofterminals to use mutually different bands. Note that the uplink anddownlink radio access schemes are not limited to these combinations, andother radio access schemes may be used.

The radio communication system 1 may be configured so that differentnumerologies are used within cells and/or between cells. Note that anumerology refers to, for example, a set of communication parameters(for example, the subcarrier spacing, the bandwidth, etc.) that are usedto transmit and receive a certain signal.

In the radio communication system 1, a downlink shared channel (PDSCH:Physical Downlink Shared CHannel), which is used by each user terminal20 on a shared basis, a broadcast channel (PBCH: Physical BroadcastCHannel), downlink L1/L2 control channels and so on are used as downlinkchannels. User data, higher layer control information and SIBs (SystemInformation Blocks) are communicated in the PDSCH. Also, the MIB (MasterInformation Block) is communicated in the PBCH.

The downlink L1/L2 control channels include a PDCCH (Physical DownlinkControl CHannel), an EPDCCH (Enhanced Physical Downlink ControlCHannel), a PCFICH (Physical Control Format Indicator CHannel), a PHICH(Physical Hybrid-ARQ Indicator CHannel) and so on. Downlink controlinformation (DCI), including PDSCH and PUSCH scheduling information, iscommunicated by the PDCCH. The number of OFDM symbols to use for thePDCCH is communicated by the PCFICH. HARQ (Hybrid Automatic RepeatreQuest) delivery acknowledgment information (also referred to as, forexample, “retransmission control information,” “HARQ-ACKs,” “ACK/NACKs,”etc.) in response to the PUSCH is transmitted by the PHICH. The EPDCCHis frequency-division-multiplexed with the PDSCH (downlink shared datachannel) and used to communicate DCI and so on, like the PDCCH.

In the radio communication system 1, an uplink shared channel (PUSCH:Physical Uplink Shared CHannel), which is used by each user terminal 20on a shared basis, an uplink control channel (PUCCH: Physical UplinkControl CHannel), a random access channel (PRACH: Physical Random AccessCHannel) and so on are used as uplink channels. User data, higher layercontrol information and so on are communicated by the PUSCH. Also,downlink radio quality information (CQI: Channel Quality Indicator),delivery acknowledgement information and so on are communicated by thePUCCH. By means of the PRACH, random access preambles for establishingconnections with cells are communicated.

In the radio communication systems 1, the cell-specific reference signal(CRS: Cell-specific Reference Signal), the channel state informationreference signal (CSI-RS: Channel State Information-Reference Signal),the demodulation reference signal (DMRS: DeModulation Reference Signal),the positioning reference signal (PRS: Positioning Reference Signal) andso on are communicated as downlink reference signals. Also, in the radiocommunication system 1, the measurement reference signal (SRS: SoundingReference Signal), the demodulation reference signal (DMRS) and so onare communicated as uplink reference signals. Note that the DMRS may bereferred to as a “user terminal-specific reference signal (UE-specificReference Signal).” Also, the reference signals to be communicated areby no means limited to these.

(Radio Base Station)

FIG. 11 is a diagram to illustrate an example of an overall structure ofa radio base station according to one embodiment of the presentinvention. A radio base station 10 has a plurality oftransmitting/receiving antennas 101, amplifying sections 102,transmitting/receiving sections 103, a baseband signal processingsection 104, a call processing section 105 and a communication pathinterface 106. Note that one or more transmitting/receiving antennas101, amplifying sections 102 and transmitting/receiving sections 103 maybe provided.

User data to be transmitted from the radio base station 10 to a userterminal 20 on the downlink is input from the higher station apparatus30 to the baseband signal processing section 104, via the communicationpath interface 106.

In the baseband signal processing section 104, the user data issubjected to a PDCP (Packet Data Convergence Protocol) layer process,user data division and coupling, RLC (Radio Link Control) layertransmission processes such as RLC retransmission control, MAC (MediumAccess Control) retransmission control (for example, an HARQ (HybridAutomatic Repeat reQuest) transmission process), scheduling, transportformat selection, channel coding, an inverse fast Fourier transform(IFFT) process and a precoding process, and the result is forwarded toeach transmitting/receiving section 103. Furthermore, downlink controlsignals are also subjected to transmission processes such as channelcoding and an inverse fast Fourier transform, and forwarded to eachtransmitting/receiving section 103.

Baseband signals that are precoded and output from the baseband signalprocessing section 104 on a per antenna basis are converted into a radiofrequency band in the transmitting/receiving sections 103, and thentransmitted. The radio frequency signals having been subjected tofrequency conversion in the transmitting/receiving sections 103 areamplified in the amplifying sections 102, and transmitted from thetransmitting/receiving antennas 101. The transmitting/receiving sections103 can be constituted by transmitters/receivers, transmitting/receivingcircuits or transmitting/receiving apparatus that can be described basedon general understanding of the technical field to which the presentinvention pertains. Note that a transmitting/receiving section 103 maybe structured as a transmitting/receiving section in one entity, or maybe constituted by a transmitting section and a receiving section.

Meanwhile, as for uplink signals, radio frequency signals that arereceived in the transmitting/receiving antennas 101 are each amplifiedin the amplifying sections 102. The transmitting/receiving sections 103receive the uplink signals amplified in the amplifying sections 102. Thereceived signals are converted into the baseband signal throughfrequency conversion in the transmitting/receiving sections 103 andoutput to the baseband signal processing section 104.

In the baseband signal processing section 104, user data that isincluded in the uplink signals that are input is subjected to a fastFourier transform (FFT) process, an inverse discrete Fourier transform(IDFT) process, error correction decoding, a MAC retransmission controlreceiving process, and RLC layer and PDCP layer receiving processes, andforwarded to the higher station apparatus 30 via the communication pathinterface 106. The call processing section 105 performs call processing(such as setting up and releasing communication channels), manages thestate of the radio base stations 10 and manages the radio resources.

The communication path interface section 106 transmits and receivessignals to and from the higher station apparatus 30 via a predeterminedinterface. Also, the communication path interface 106 may transmit andreceive signals (backhaul signaling) with other radio base stations 10via an inter-base station interface (which is, for example, opticalfiber that is in compliance with the CPRI (Common Public RadioInterface), the X2 interface, etc.).

The transmitting/receiving sections 103 transmit a control resource setand/or a common control channel (FIG. 2 to FIG. 9). In addition, thetransmitting/receiving sections 103 allocate downlink data over apredetermined frequency field from the same time location, or allocatedownlink data to the predetermined frequency field from varying timelocations, and report the schedule of the downlink data using the abovecontrol resource set or common control channel.

FIG. 12 is a diagram to illustrate an example of functional structure ofa radio base station according to one embodiment of the presentinvention. Note that, although this example primarily illustratesfunctional blocks that pertain to characteristic parts of the presentembodiment, the radio base station 10 has other functional blocks thatare necessary for radio communication as well.

The baseband signal processing section 104 has a control section(scheduler) 301, a transmission signal generation section 302, a mappingsection 303, a received signal processing section 304 and a measurementsection 305. Note that these configurations have only to be included inthe radio base station 10, and some or all of these configurations maynot be included in the baseband signal processing section 104.

The control section (scheduler) 301 controls the whole of the radio basestation 10. The control section 301 can be constituted by a controller,a control circuit or control apparatus that can be described based ongeneral understanding of the technical field to which the presentinvention pertains.

The control section 301, for example, controls the generation of signalsin the transmission signal generation section 302, the allocation ofsignals by the mapping section 303, and so on. Furthermore, the controlsection 301 controls the signal receiving processes in the receivedsignal processing section 304, the measurements of signals in themeasurement section 305, and so on.

The control section 301 controls the scheduling (for example, resourceallocation) of system information, downlink data signals (for example,signals transmitted in the PDSCH) and downlink control signals (forexample, signals communicated in downlink control channels). Also, thecontrol section 301 controls the generation of downlink control signals(for example, delivery acknowledgement information and so on), downlinkdata signals and so on, based on whether or not retransmission controlis necessary, which is decided in response to uplink data signals, andso on. Also, the control section 301 controls the scheduling ofsynchronization signals (for example, the PSS (Primary SynchronizationSignal)/SSS (Secondary Synchronization Signal)), downlink referencesignals (for example, the CRS, the CSI-RS, the DMRS, etc.) and so on.

In addition, the control section 301 controls the scheduling of uplinkdata signals (for example, signals transmitted in the PUSCH), uplinkcontrol signals (for example, signals transmitted in the PUCCH and/orthe PUSCH), random access preambles transmitted in the PRACH, uplinkreference signals, and so on.

The control section 301 controls transmission of control resource setsand downlink data. Furthermore, the control section 301 controlstransmission of a common control channel. The control section 301allocates downlink data over a predetermined frequency field from thesame time location or allocates downlink data to the predeterminedfrequency field from varying time locations, and reports the schedule ofthe downlink data using the above control resource set or common controlchannel (FIG. 2 to FIG. 8).

Upon allocating downlink data, the control section 301 exerts control sothat downlink control information included in a control resource set anddownlink data are allocated not to overlapping each other, or downlinkcontrol information included in a control resource set and downlink dataare allocated to overlap each other. The control section 301 may applyrate matching and/or a puncturing process to the overlapping part of thedownlink control information and the downlink data.

The transmission signal generation section 302 generates downlinksignals (downlink control signals, downlink data signals, downlinkreference signals and so on) based on commands from the control section301, and outputs these signals to the mapping section 303. Thetransmission signal generation section 302 can be constituted by asignal generator, a signal generating circuit or signal generatingapparatus that can be described based on general understanding of thetechnical field to which the present invention pertains.

For example, the transmission signal generation section 302 generates DLassignments, which report downlink signal allocation information, and ULgrants, which report uplink signal allocation information, based oncommands from the control section 301. Also, the downlink data signalsare subjected to the coding process, the modulation process and so on,by using coding rates and modulation schemes that are determined basedon, for example, channel state information (CSI) from each user terminal20.

The mapping section 303 maps the downlink signals generated in thetransmission signal generation section 302 to predetermined radioresources based on commands from the control section 301, and outputsthese to the transmitting/receiving sections 103. The mapping section303 can be constituted by a mapper, a mapping circuit or mappingapparatus that can be described based on general understanding of thetechnical field to which the present invention pertains.

The received signal processing section 304 performs receiving processes(for example, demapping, demodulation, decoding and so on) of receivedsignals that are input from the transmitting/receiving sections 103.Here, the received signals include, for example, uplink signalstransmitted from the user terminals 20 (uplink control signals, uplinkdata signals, uplink reference signals and so on). For the receivedsignal processing section 304, a signal processor, a signal processingcircuit or signal processing apparatus that can be described based ongeneral understanding of the technical field to which the presentinvention pertains can be used.

The received signal processing section 304 outputs the decodedinformation acquired through the receiving processes to the controlsection 301. For example, when a PUCCH to contain an HARQ-ACK isreceived, the received signal processing section 304 outputs thisHARQ-ACK to the control section 301. Also, the received signalprocessing section 304 outputs the received signals and/or the signalsafter the receiving processes to the measurement section 305.

The measurement section 305 conducts measurements with respect to thereceived signals. The measurement section 305 can be constituted by ameasurer, a measurement circuit or measurement apparatus that can bedescribed based on general understanding of the technical field to whichthe present invention pertains.

When signals are received, the measurement section 305 may measure, forexample, the received power (for example, RSRP (Reference SignalReceived Power)), the received quality (for example, RSRQ (ReferenceSignal Received Quality)), SINR (Signal to Interference plus NoiseRatio) and/or the like), uplink channel information (for example CSI)and so on. The measurement results may be output to the control section301.

(User Terminal)

FIG. 13 is a diagram to illustrate an example of an overall structure ofa user terminal according to one embodiment of the present invention. Auser terminal 20 has a plurality of transmitting/receiving antennas 201,amplifying sections 202, transmitting/receiving sections 203, a basebandsignal processing section 204 and an application section 205. Note thatone or more transmitting/receiving antennas 201, amplifying sections 202and transmitting/receiving sections 203 may be provided.

Radio frequency signals that are received in the transmitting/receivingantennas 201 are amplified in the amplifying sections 202. Thetransmitting/receiving sections 203 receive the downlink signalsamplified in the amplifying sections 202. The received signals aresubjected to frequency conversion and converted into the baseband signalin the transmitting/receiving sections 203, and output to the basebandsignal processing section 204. A transmitting/receiving section 203 canbe constituted by a transmitters/receiver, a transmitting/receivingcircuit or transmitting/receiving apparatus that can be described basedon general understanding of the technical field to which the presentinvention pertains. Note that a transmitting/receiving section 203 maybe structured as a transmitting/receiving section in one entity, or maybe constituted by a transmitting section and a receiving section.

In the baseband signal processing section 204, the baseband signal thatis input is subjected to an FFT process, error correction decoding, aretransmission control receiving process, and so on. Downlink user datais forwarded to the application section 205. The application section 205performs processes related to higher layers above the physical layer andthe MAC layer, and so on. Also, among the downlink data, the broadcastinformation may also be forwarded to the application section 205.

Meanwhile, uplink user data is input from the application section 205 tothe baseband signal processing section 204. The baseband signalprocessing section 204 performs a retransmission control transmissionprocess (for example, an HARQ transmission process), channel coding,precoding, a discrete Fourier transform (DFT) process, an IFFT processand so on, and the result is forwarded to the transmitting/receivingsections 203. Baseband signals that are output from the baseband signalprocessing section 204 are converted into a radio frequency band in thetransmitting/receiving sections 203 and transmitted. The radio frequencysignals that are subjected to frequency conversion in thetransmitting/receiving sections 203 are amplified in the amplifyingsections 202, and transmitted from the transmitting/receiving antennas201.

The transmitting/receiving sections 203 receive a control resource setand/or a common control channel (FIG. 2 to FIG. 9). In addition, thetransmitting/receiving sections 103 receive downlink data, the scheduleof which is reported in the control resource set or the common controlchannel, and which is allocated over a predetermined frequency fieldfrom the same time location or allocated to the predetermined frequencyfield from varying time locations.

FIG. 14 is a diagram to illustrate an example of a functional structureof a user terminal according to one embodiment of the present invention.Note that, although this example primarily illustrates functional blocksthat pertain to characteristic parts of the present embodiment, the userterminal 20 has other functional blocks that are necessary for radiocommunication as well.

The baseband signal processing section 204 provided in the user terminal20 at least has a control section 401, a transmission signal generationsection 402, a mapping section 403, a received signal processing section404 and a measurement section 405. Note that these configurations haveonly to be included in the user terminal 20, and some or all of theseconfigurations may not be included in the baseband signal processingsection 204.

The control section 401 controls the whole of the user terminal 20. Forthe control section 401, a controller, a control circuit or controlapparatus that can be described based on general understanding of thetechnical field to which the present invention pertains can be used.

The control section 401, for example, controls the generation of signalsin the transmission signal generation section 402, the allocation ofsignals in the mapping section 403, and so on. Furthermore, the controlsection 401 controls the signal receiving processes in the receivedsignal processing section 404, the measurements of signals in themeasurement section 405, and so on.

The control section 401 acquires the downlink control signals (forexample, signals transmitted in downlink control channels) and downlinkdata signals (for example, signals transmitted in the PDSCH) transmittedfrom the radio base station 10, via the received signal processingsection 404. The control section 401 controls the generation of uplinkcontrol signals (for example, delivery acknowledgement information andso on) and/or uplink data signals based on whether or not retransmissioncontrol is necessary, which is decided in response to downlink controlsignals and/or downlink data signals, and so on.

The control section 401 controls receipt of a control resource set anddownlink data. Furthermore, the control section 401 controls receipt ofa common control channel. The control section 401 controls the receivingprocesses (decoding process and other processes) of downlink data, theschedule of which is reported in the control resource set or the commoncontrol channel, and which is allocated over a predetermined frequencyfield from the same time location or allocated to the predeterminedfrequency field from varying time locations (FIG. 2 to FIG. 8).

The downlink control information included in the control resource setand the downlink data are allocated not to overlap each other, or thedownlink control information included in the control resource set andthe downlink data are allocated to overlap each other. The controlsection 401 may apply rate matching and/or a puncturing process(processes including de-rate matching and/or depuncturing) to theoverlapping part of the downlink control information and the downlinkdata.

The transmission signal generation section 402 generates uplink signals(uplink control signals, uplink data signals, uplink reference signalsand so on) based on commands from the control section 401, and outputsthese signals to the mapping section 403. The transmission signalgeneration section 402 can be constituted by a signal generator, asignal generating circuit or signal generating apparatus that can bedescribed based on general understanding of the technical field to whichthe present invention pertains.

For example, the transmission signal generation section 402 generatesuplink control signals related to delivery acknowledgement information,channel state information (CSI) and so on, based on commands from thecontrol section 401. Also, the transmission signal generation section402 generates uplink data signals based on commands from the controlsection 401. For example, when a UL grant is included in a downlinkcontrol signal that is reported from the radio base station 10, thecontrol section 401 commands the transmission signal generation section402 to generate an uplink data signal.

The mapping section 403 maps the uplink signals generated in thetransmission signal generation section 402 to radio resources based oncommands from the control section 401, and outputs the result to thetransmitting/receiving sections 203. The mapping section 403 can beconstituted by a mapper, a mapping circuit or mapping apparatus that canbe described based on general understanding of the technical field towhich the present invention pertains.

The received signal processing section 404 performs receiving processes(for example, demapping, demodulation, decoding and so on) of receivedsignals that are input from the transmitting/receiving sections 203.Here, the received signals include, for example, downlink signals(downlink control signals, downlink data signals, downlink referencesignals and so on) that are transmitted from the radio base station 10.The received signal processing section 404 can be constituted by asignal processor, a signal processing circuit or signal processingapparatus that can be described based on general understanding of thetechnical field to which the present invention pertains. Also, thereceived signal processing section 404 can constitute the receivingsection according to the present invention.

The received signal processing section 404 outputs the decodedinformation, acquired through the receiving processes, to the controlsection 401. The received signal processing section 404 outputs, forexample, broadcast information, system information, RRC signaling, DCIand so on, to the control section 401. Also, the received signalprocessing section 404 outputs the received signals and/or the signalsafter the receiving processes to the measurement section 405.

The measurement section 405 conducts measurements with respect to thereceived signals. For example, the measurement section 405 performsmeasurements using downlink reference signals transmitted from the radiobase station 10. The measurement section 405 can be constituted by ameasurer, a measurement circuit or measurement apparatus that can bedescribed based on general understanding of the technical field to whichthe present invention pertains.

The measurement section 405 may measure, for example, the received power(for example, RSRP), the received quality (for example, RSRQ, receivedSINR), down link channel information (for example CSI) and so on of thereceived signals. The measurement results may be output to the controlsection 401.

(Hardware Structure)

Note that the block diagrams that have been used to describe the aboveembodiments illustrate blocks in functional units. These functionalblocks (components) may be implemented in arbitrary combinations ofhardware and/or software. Also, the means for implementing eachfunctional block is not particularly limited. That is, each functionalblock may be realized by one piece of apparatus that is physicallyand/or logically aggregated, or may be realized by directly and/orindirectly connecting two or more physically and/or logically separatepieces of apparatus (via wire or wireless, for example) and using thesemultiple pieces of apparatus.

For example, the radio base station, user terminals and so on accordingto embodiments of the present invention may function as a computer thatexecutes the processes of the radio communication method of the presentinvention. FIG. 15 is a diagram to illustrate an example hardwarestructure of a radio base station and a user terminal according to anembodiment of the present invention. Physically, the above-describedradio base stations 10 and user terminals 20 may be formed as a computerapparatus that includes a processor 1001, a memory 1002, a storage 1003,communication apparatus 1004, input apparatus 1005, output apparatus1006 and a bus 1007.

Note that, in the following description, the word “apparatus” may bereplaced by “circuit,” “device,” “unit” and so on. Note that thehardware structure of a radio base station 10 and a user terminal 20 maybe designed to include one or more of each apparatus illustrated in thedrawings, or may be designed not to include part of the apparatus.

For example, although only one processor 1001 is illustrated, aplurality of processors may be provided. Furthermore, processes may beimplemented with one processor, or processes may be implemented insequence, or in different manners, on two or more processors. Note thatthe processor 1001 may be implemented with one or more chips.

Each function of the radio base station 10 and the user terminal 20 isimplemented by reading predetermined software (program) on hardware suchas the processor 1001 and the memory 1002, and by controlling thecalculations in the processor 1001, the communication in thecommunication apparatus 1004, and the reading and/or writing of data inthe memory 1002 and the storage 1003.

The processor 1001 may control the whole computer by, for example,running an operating system. The processor 1001 may be configured with acentral processing unit (CPU), which includes interfaces with peripheralapparatus, control apparatus, computing apparatus, a register and so on.For example, the above-described baseband signal processing section 104(204), call processing section 105 and so on may be implemented by theprocessor 1001.

Furthermore, the processor 1001 reads programs (program codes), softwaremodules or data, from the storage 1003 and/or the communicationapparatus 1004, into the memory 1002, and executes various processesaccording to these. As for the programs, programs to allow computers toexecute at least part of the operations of the above-describedembodiments may be used. For example, the control section 401 of theuser terminals 20 may be implemented by control programs that are storedin the memory 1002 and that operate on the processor 1001, and otherfunctional blocks may be implemented likewise.

The memory 1002 is a computer-readable recording medium, and may beconstituted by, for example, at least one of a ROM (Read Only Memory),an EPROM (Erasable Programmable ROM), an EEPROM (Electrically EPROM), aRAM (Random Access Memory) and/or other appropriate storage media. Thememory 1002 may be referred to as a “register,” a “cache,” a “mainmemory” (primary storage apparatus) and so on. The memory 1002 can storeexecutable programs (program codes), software modules and/or the likefor implementing the radio communication methods according toembodiments of the present invention.

The storage 1003 is a computer-readable recording medium, and may beconstituted by, for example, at least one of a flexible disk, a floppy(registered trademark) disk, a magneto-optical disk (for example, acompact disc (CD-ROM (Compact Disc ROM) and so on), a digital versatiledisc, a Blu-ray (registered trademark) disk), a removable disk, a harddisk drive, a smart card, a flash memory device (for example, a card, astick, a key drive, etc.), a magnetic stripe, a database, a server,and/or other appropriate storage media. The storage 1003 may be referredto as “secondary storage apparatus.”

The communication apparatus 1004 is hardware (transmitting/receivingdevice) for allowing inter-computer communication by using wired and/orwireless networks, and may be referred to as, for example, a “networkdevice,” a “network controller,” a “network card,” a “communicationmodule” and so on. The communication apparatus 1004 may be configured toinclude a high frequency switch, a duplexer, a filter, a frequencysynthesizer and so on in order to realize, for example, frequencydivision duplex (FDD) and/or time division duplex (TDD). For example,the above-described transmitting/receiving antennas 101 (201),amplifying sections 102 (202), transmitting/receiving sections 103(203), communication path interface 106 and so on may be implemented bythe communication apparatus 1004.

The input apparatus 1005 is an input device for receiving input from theoutside (for example, a keyboard, a mouse, a microphone, a switch, abutton, a sensor and so on). The output apparatus 1006 is an outputdevice for allowing sending output to the outside (for example, adisplay, a speaker, an LED (Light Emitting Diode) lamp and so on). Notethat the input apparatus 1005 and the output apparatus 1006 may beprovided in an integrated structure (for example, a touch panel).

Furthermore, these pieces of apparatus, including the processor 1001,the memory 1002 and so on are connected by the bus 1007 so as tocommunicate information. The bus 1007 may be formed with a single bus,or may be formed with buses that vary between pieces of apparatus.

Also, the radio base station 10 and the user terminal 20 may bestructured to include hardware such as a microprocessor, a digitalsignal processor (DSP), an ASIC (Application-Specific IntegratedCircuit), a PLD (Programmable Logic Device), an FPGA (Field ProgrammableGate Array) and so on, and part or all of the functional blocks may beimplemented by the hardware. For example, the processor 1001 may beimplemented with at least one of these pieces of hardware.

(Variations)

Note that the terminology used in this specification and the terminologythat is needed to understand this specification may be replaced by otherterms that convey the same or similar meanings. For example, “channels”and/or “symbols” may be replaced by “signals (or “signaling”).” Also,“signals” may be “messages.” A reference signal may be abbreviated as an“RS,” and may be referred to as a “pilot,” a “pilot signal” and so on,depending on which standard applies. Furthermore, a “component carrier”(CC) may be referred to as a “cell,” a “frequency carrier,” a “carrierfrequency” and so on.

Furthermore, a radio frame may be comprised of one or more periods(frames) in the time domain. Each of one or more periods (frames)constituting a radio frame may be referred to as a “subframe.”Furthermore, a subframe may be comprised of one or more slots in thetime domain. A subframe may be a fixed time duration (for example, onems) not dependent on the neurology.

Furthermore, a slot may be comprised of one or more symbols in the timedomain (OFDM (Orthogonal Frequency Division Multiplexing) symbols,SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, andso on). Also, a slot may be a time unit based on neurology. Also, a slotmay include a plurality of mini-slots. Each mini-slot may consist of oneor more symbols in the time domain. Also, a mini-slot may be referred toas a “subslot.”

A radio frame, a subframe, a slot, a mini-slot and a symbol allrepresent the time unit in signal communication. A radio frame, asubframe, a slot, a mini-slot and a symbol may be each called by otherapplicable names. For example, one subframe may be referred to as a“transmission time interval” (TTI), or a plurality of consecutivesubframes may be referred to as a “TTI,” or one slot or mini-slot may bereferred to as a “TTI.” That is, a subframe and/or a TTI may be asubframe (one ms) in existing LTE, may be a shorter period than one ms(for example, one to thirteen symbols), or may be a longer period oftime than one ms. Note that the unit to represent the TTI may bereferred to as a “slot,” a “mini slot” and so on, instead of a“subframe.”

Here, a TTI refers to the minimum time unit of scheduling in radiocommunication, for example. For example, in LTE systems, a radio basestation schedules the radio resources (such as the frequency bandwidthand transmission power that can be used in each user terminal) toallocate to each user terminal in TTI units. Note that the definition ofTTIs is not limited to this.

The TTI may be the transmission time unit of channel-encoded datapackets (transport blocks), code blocks and/or codewords, or may be theunit of processing in scheduling, link adaptation and so on. Note thatwhen a TTI is given, the time interval (for example, the number ofsymbols) in which transport blocks, code blocks and/or codewords areactually mapped may be shorter than the TTI.

Note that, when one slot or one mini-slot is referred to as a “TTI,” oneor more TTIs (that is, one or more slots or one or more mini-slots) maybe the minimum time unit of scheduling. Also, the number of slots (thenumber of mini-slots) to constitute this minimum time unit of schedulingmay be controlled.

A TTI having a time duration of one ms may be referred to as a “normalTTI” (TTI in LTE Rel. 8 to 12), a “long TTI,” a “normal subframe,” a“long subframe,” and so on. A TTI that is shorter than a normal TTI maybe referred to as a “shortened TTI,” a “short TTI,” “a partial TTI” (ora “fractional TTI”), a “shortened subframe,” a “short subframe,” a“mini-slot,” “a sub-slot” and so on.

Note that a long TTI (for example, a normal TTI, a subframe, etc.) maybe replaced with a TTI having a time duration exceeding one ms, and ashort TTI (for example, a shortened TTI) may be replaced with a TTIhaving a TTI length less than the TTI length of a long TTI and not lessthan one ms.

A resource block (RB) is the unit of resource allocation in the timedomain and the frequency domain, and may include one or a plurality ofconsecutive subcarriers in the frequency domain. Also, an RB may includeone or more symbols in the time domain, and may be one slot, onemini-slot, one subframe or one TTI in length. One TTI and one subframeeach may be comprised of one or more resource blocks. Note that one ormore RBs may be referred to as a “physical resource block (PRB: PhysicalRB),” a “subcarrier group (SCG),” a “resource element group (REG),” a“PRB pair,” an “RB pair” and so on.

Furthermore, a resource block may be comprised of one or more resourceelements (REs). For example, one RE may be a radio resource field of onesubcarrier and one symbol.

Note that the structures of radio frames, subframes, slots, mini-slots,symbols and so on described above are merely examples. For example,configurations pertaining to the number of subframes included in a radioframe, the number of slots included in a subframe, the number ofmini-slots included in a slot, the number of symbols and RBs included ina slot or a mini-slot, the number of subcarriers included in an RB, thenumber of symbols in a TTI, the symbol duration, the length of cyclicprefixes (CPs) and so on can be variously changed.

Also, the information and parameters described in this specification maybe represented in absolute values or in relative values with respect topredetermined values, or may be represented in other informationformats. For example, radio resources may be specified by predeterminedindices. In addition, equations to use these parameters and so on may beused, apart from those explicitly disclosed in this specification.

The names used for parameters and so on in this specification are in norespect limiting. For example, since various channels (PUCCH (PhysicalUplink Control Channel), PDCCH (Physical Downlink Control Channel) andso on) and information elements can be identified by any suitable names,the various names assigned to these individual channels and informationelements are in no respect limiting.

The information, signals and/or others described in this specificationmay be represented by using a variety of different technologies. Forexample, data, instructions, commands, information, signals, bits,symbols and chips, all of which may be referenced throughout theherein-contained description, may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orphotons, or any combination of these.

Also, information, signals and so on can be output from higher layers tolower layers and/or from lower layers to higher layers. Information,signals and so on may be input and output via a plurality of networknodes.

The information, signals and so on that are input may be transmitted toother pieces of apparatus. The information, signals and so on to beinput and/or output can be overwritten, updated or appended. Theinformation, signals and so on that are output may be deleted. Theinformation, signals and so on that are input may be transmitted toother pieces of apparatus.

Reporting of information is by no means limited to theexamples/embodiments described in this specification, and other methodsmay be used as well. For example, reporting of information may beimplemented by using physical layer signaling (for example, downlinkcontrol information (DCI), uplink control information (UCI), higherlayer signaling (for example, RRC (Radio Resource Control) signaling,broadcast information (the master information block (MIB), systeminformation blocks (SIBs) and so on), MAC (Medium Access Control)signaling and so on), and other signals and/or combinations of these.

Note that physical layer signaling may be referred to as “L1/L2 (Layer1/Layer 2) control information” (L1/L2 control signals), “L1 controlinformation” (L1 control signal) and so on. Also, RRC signaling may bereferred to as “RRC messages,” and can be, for example, an RRCconnection setup message, RRC connection reconfiguration message, and soon. Also, MAC signaling may be reported using, for example, MAC controlelements (MAC CEs (Control Elements)).

Also, reporting of predetermined information (for example, reporting ofinformation to the effect that “X holds”) does not necessarily have tobe sent explicitly, and can be sent implicitly (by, for example, notreporting this piece of information). Decisions may be made in valuesrepresented by one bit (0 or 1), may be made in Boolean values thatrepresent true or false, or may be made by comparing numerical values(for example, comparison against a predetermined value).

Software, whether referred to as “software,” “firmware,” “middleware,”“microcode” or “hardware description language,” or called by othernames, should be interpreted broadly, to mean instructions, instructionsets, code, code segments, program codes, programs, subprograms,software modules, applications, software applications, softwarepackages, routines, subroutines, objects, executable files, executionthreads, procedures, functions and so on.

Also, software, commands, information and so on may be transmitted andreceived via communication media. For example, when software istransmitted from a website, a server or other remote sources by usingwired technologies (coaxial cables, optical fiber cables, twisted-paircables, digital subscriber lines (DSL) and so on) and/or wirelesstechnologies (infrared radiation, microwaves and so on), these wiredtechnologies and/or wireless technologies are also included in thedefinition of communication media.

The terms “system” and “network” as used herein are usedinterchangeably.

As used herein, the terms “base station (BS),” “radio base station,”“eNB,” “cell,” “sector,” “cell group,” “carrier,” and “componentcarrier” may be used interchangeably. A base station may be referred toas a “fixed station,” “NodeB,” “eNodeB (eNB),” “access point,”“transmission point,” “receiving point,” “femto cell,” “small cell” andso on.

A base station can accommodate one or more (for example, three) cells(also referred to as “sectors”). When a base station accommodates aplurality of cells, the entire coverage area of the base station can bepartitioned into multiple smaller areas, and each smaller area canprovide communication services through base station subsystems (forexample, indoor small base stations (RRHs: Remote Radio Heads)). Theterm “cell” or “sector” refers to part or all of the coverage area of abase station and/or a base station subsystem that provides communicationservices within this coverage.

As used herein, the terms “mobile station (MS)” “user terminal,” “userequipment (UE)” and “terminal” may be used interchangeably. A basestation may be referred to as a “fixed station,” “NodeB,” “eNodeB(eNB),” “access point,” “transmission point,” “receiving point,” “femtocell,” “small cell” and so on.

A mobile station may be referred to, by a person skilled in the art, asa “subscriber station,” “mobile unit,” “subscriber unit,” “wirelessunit,” “remote unit,” “mobile device,” “wireless device,” “wirelesscommunication device,” “remote device,” “mobile subscriber station,”“access terminal,” “mobile terminal,” “wireless terminal,” “remoteterminal,” “handset,” “user agent,” “mobile client,” “client” or someother suitable terms.

Furthermore, the radio base stations in this specification may beinterpreted as user terminals. For example, each aspect/embodiment ofthe present invention may be applied to a configuration in whichcommunication between a radio base station and a user terminal isreplaced with communication among a plurality of user terminals (D2D:Device-to-Device). In this case, user terminals 20 may have thefunctions of the radio base stations 10 described above. In addition,terms such as “uplink” and “downlink” may be interpreted as “side.” Forexample, an uplink channel may be interpreted as a side channel.

Likewise, the user terminals in this specification may be interpreted asradio base stations. In this case, the radio base stations 10 may havethe functions of the user terminals 20 described above.

Certain actions which have been described in this specification to beperformed by base station may, in some cases, be performed by uppernodes. In a network comprised of one or more network nodes with basestations, it is clear that various operations that are performed tocommunicate with terminals can be performed by base stations, one ormore network nodes (for example, MMEs (Mobility Management Entities),S-GW (Serving-Gateways), and so on may be possible, but these are notlimiting) other than base stations, or combinations of these.

The examples/embodiments illustrated in this specification may be usedindividually or in combinations, which may be switched depending on themode of implementation. The order of processes, sequences, flowchartsand so on that have been used to describe the examples/embodimentsherein may be re-ordered as long as inconsistencies do not arise. Forexample, although various methods have been illustrated in thisspecification with various components of steps in exemplary orders, thespecific orders that are illustrated herein are by no means limiting.

Note that the radio communication system 1 may be applied to systemsthat use LTE (Long Term Evolution), LTE-A (LTE-Advanced), LTE-B(LTE-Beyond), SUPER 3G, IMT-Advanced, 4G (4th generation mobilecommunication system), 5G (5th generation mobile communication system),FRA (Future Radio Access), New-RAT (Radio Access Technology), NR (NewRadio), NX (New radio access), FX (Future generation radio access), GSM(Global System for Mobile communications) (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registeredtrademark)), IEEE 802.16 (WiMAX(registered trademark)), IEEE 802.20, WB(Ultra-WideBand), Bluetooth (registered trademark) and other appropriateradio communication technologies, and/or may be applied tonext-generation systems that are enhanced base on these radiocommunication technologies.

The phrase “based on” as used in this specification does not mean “basedonly on,” unless otherwise specified. In other words, the phrase “basedon” means both “based only on” and “based at least on.”

Reference to elements with designations such as “first,” “second” and soon as used herein does not generally limit the number/quantity or orderof these elements. These designations are used only for convenience, asa method for distinguishing between two or more elements. In this way,reference to the first and second elements does not imply that only twoelements may be employed, or that the first element must precede thesecond element in some way.

The terms “judge” and “determine” as used herein may encompass a widevariety of actions. For example, to “judge” and “determine” as usedherein may be interpreted to mean making judgements and determinationsrelated to calculating, computing, processing, deriving, investigating,looking up (for example, searching a table, a database or some otherdata structure, ascertaining and so on. Furthermore, to “judge” and“determine” as used herein may be interpreted to mean making judgementsand determinations related to receiving (for example, receivinginformation), transmitting (for example, transmitting information),inputting, outputting, accessing (for example, accessing data in amemory) and so on. In addition, to “judge” and “determine” as usedherein may be interpreted to mean making judgements and determinationsrelated to resolving, selecting, choosing, establishing, comparing andso on. In other words, to “judge” and “determine” as used herein may beinterpreted to mean making judgements and determinations related to someaction.

As used herein, the terms “connected” and “coupled,” or any variation ofthese terms, mean all direct or indirect connections or coupling betweentwo or more elements, and may include the presence of one or moreintermediate elements between two elements that are “connected” or“coupled” to each other. The coupling or connection between the elementsmay be physical, logical or a combination thereof. For example,“connection” may be interpreted as “access.” As used herein, twoelements may be considered “connected” or “coupled” to each other byusing one or more electrical wires, cables and/or printed electricalconnections, and, as a number of non-limiting and non-inclusiveexamples, by using electromagnetic energy, such as electromagneticenergy having wavelengths in the radio frequency, microwave and opticalregions (both visible and invisible).

When terms such as “include,” “comprise” and variations of these areused in this specification or in claims, these terms are intended to beinclusive, in a manner similar to the way the term “provide” is used.Furthermore, the term “or” as used in this specification or in claims isintended to be not an exclusive disjunction.

Now, although the present invention has been described in detail above,it should be obvious to a person skilled in the art that the presentinvention is by no means limited to the embodiments described herein.The present invention can be implemented with various corrections and invarious modifications, without departing from the spirit and scope ofthe present invention defined by the recitations of claims.Consequently, the description herein is provided only for the purpose ofexplaining examples, and should by no means be construed to limit thepresent invention in any way.

1. An apparatus comprising: a receiver that receives downlink controlinformation that is used for scheduling of a downlink shared channel,via a downlink control channel in a control resource set; a processorthat determines a starting location in a time domain of the downlinkshared channel based on the downlink control information; and an outputdevice that performs output based on downlink data signal in thedownlink shared channel, wherein when the downlink shared channeloverlaps with the control resource set, a resource to which the downlinkcontrol information is mapped is not available for the downlink sharedchannel, and wherein a field value in the downlink control informationindicates an index for designating one of a plurality of startinglocations that are provided in advance.
 2. The apparatus according toclaim 1, wherein the output apparatus is at least one of a display or aspeaker.
 3. The apparatus according to claim 1, wherein the outputapparatus is a touch panel.
 4. A system comprising a base station and anapparatus, wherein the base station comprises: a transmitter thattransmits downlink control information that is used for scheduling of adownlink shared channel, via a downlink control channel in a controlresource set; and a processor that designates a starting location in atime domain of the downlink shared channel based on the downlink controlinformation, wherein when the downlink shared channel overlaps with thecontrol resource set, a resource to which the downlink controlinformation is mapped is not available for the downlink shared channel,and wherein a field value in the downlink control information indicatesan index for designating one of a plurality of starting locations thatare provided in advance, and the apparatus comprises: a receiver thatreceives the downlink control information; a processor that determines astarting location in a time domain of the downlink shared channel basedon the downlink control information; and an output device that performsoutput based on downlink data signal in the downlink shared channel.